Propulsion unit for descaling apparatus



July 26, 1966 A. J. REINHART 3,262,143

PROPULSION UNIT FOR DESCALING APPARATUS Filed April 6, 1964 5 Sheets-5heet 1 Fly. 7

5y WW2 July 26, 1966 A. J. REINHART PROPULSION UNIT FOR DESCALING APPARATUS 5 Sheets-Sheet 2 Filed April 6, 1964 y 6, 1966 A. J. REINHART 3,262,143

PROPULSION UNIT FOR DESCALING APPARATUS Filed April 6, 1964 5 Sheets-Sheet 3 Fig. 5 Fig. 6

Jn van for 1416157970 JOA A/V/VACV/Y VJ/PT United States Patent 3,262,143 PROPULSION UNIT FOR DESCALING APPARATUS Alberto Johann Reinhart, Villa Margherita, Ponte Tresa, Switzerland Filed Apr. 6, 1964, Ser. No. 357,716 Claims priority, application Switzerland, Apr. 5, 1963,

4,207/ 63 8 Claims. (Cl. -104.06)

The present invention relates to descaling apparatus for descaling and cleaning canalization installations such as industrial pipes, sewers, conduits and the like. More in particular, the invention concerns propulsion means for descaling apparatus incorporating components adapted to generate water hammer blows.

Apparatus .for descaling conduits such as pipes comprises -among other components, tools fitted around a shaft provided with cutters disposed radially to score or scrape the incrustations. Generally these cutters end with two V-shaped blades to remove the notched incrustations, to smash and detach it from the internal wall of the canalization. Scrapers and some shaft centering tools are pulled elastically against the internal wall of the conduit, and a propulsion unit pushes the apparatus forward by the fluid pressure. The propulsion unit may be a rotating one.

In general, such a unit comprises a tapered frustum cup mounted on the shaft, the largest edge of which rests on the internal wall of the canalization, so that the fluid pressure pushing against the interior hollowed surface of the cup creates the thrust required to move the descaling apparatus forward.

With all these propulsion devices, the internal section of the pipe is completely obstructed by the propulsion device itself, only some orifices are provided to let a part of the fluid pass forward in order to expel the incrustations in front of the apparatus.

The propulsion devices known from the prior art are operated only by the fluid pressure, and they function simply as a piston, using only the static pressure.

The propulsion unit in accordance with the invention utilizes, besides the simple fluid pressure, the dynamic pressure created by repeated water hammer strokes, which increases the power of the propulsion device enormously and thereby the eflicacy of the apparatus to smash the incrustations.

The propulsion unit according to the invention is distinguished by two propulsion devices of the same construction connected to a central carrying shaft, between which there is a centering device for the propulsion unit in the pipe. Each propulsion device comprises a set of elastic sections fixed angularly equidistant to the back of a plate perpendicular to the central shaft. These sections are inclined backwards and loaded with a heavy slab. The outward edges of the section-s rest against the inner surface of the pipe. A space is left between one section and the following one permitting the flow of water. The elements are arranged in a manner that, automatically and alternatively, under the pushing action of the water, both sections of the propulsion devices are held against their carrying plate. Each momentary stop of the sections creates a water hammer effect which considerably increases the pushing'force of the propulsion unit.

Further objects :and advantages of the invention will become apparent from the following description. with reference to the accompanying drawings which show, by way of example, a structural form of the propulsion unit in accordance with the invention, and in which:

FIG. 1 shows a longitudinal sectional view of the propulsion unit taken along line II of FIG. 2,

FIG. 2 shows a sectional end view of the propulsion unit taken along line IIII of FIG. 1,

' FIG. 3 shows, to an enlarged scale, one element of one 3,26ZJ43 Patented July 26, 1366 of the propulsion devices seen in the direction of the arrow in FIG. 1,

FIG. 4 shows a sectional View taken along line IV-IV in FIG. 3,

FIG. 5 shows a front view of one of the centering arms of the propulsion unit, and

FIG. 6 shows the same centering arm in side view.

In the propulsion unit 1 is the central shaft on which are mounted all the elements of the propulsion unit. This propulsion unit comprises three parts, an anterior propulsion device 3, a posterior propulsion device 5 and a centering device 7, 8 placed between the two propulsion devices.

The shaft 1 has at its ends toggle loops 2 in order to be connected with the descaling devices which are ahead of it and at its rear. These devices are described in detail in Swiss Patent No. 367,361 of the applicant. First the centering device is described which is placed between the propulsion devices 3 and 5. This device comprises two similar parts each having asocket 9 or 10 provided with a setting collar 12 or .18, and having each six radial hinge knuckles 13 or 19, placed at angles of 60 relative to one another. The hinge knuckles 13 are displaced by a 30 angle with respect to the hinge knuckles 19. Upon the hinge knuckles 13 other hinge connections 14- are provided, similarly the sockets 20 are pivotally connected to knuckles 19. The flexible arms 15 and 21 are connected to members 14 and 20, respectively.

Each flexible arm 15 and 21 carries at its outward end a roller 16 or 22, which rests against the internal surface of the pipe 17 which is to be cleaned. The roller carrying arms of both devices being identical, an arm of the anterior centering device 7 is now described with refer once to FIGS. 5 and 6. The drawings show the hinge knuckle 13 which supports by means of a pin 28 the hinge knuckle 14 which has a slot 29 in which one end of a flexible steel blade is received acting as a flexible arm 15. The hinge knuckle and the flexible blades are fixed together by means of two screws 30 extending therethrough. The blades are provided with oval holes so that the arm 15 may move a few degrees in its plane, in case some'transversal forces are encountered during the propulsion action. The other ends of the steel blades are secured in a similar manner by means of screw 34 in the slot 33 provided between the jaws of a frame 32. Also here the holes on the blades are of oval shape. The frame 32 is provided with a three-thonged fork 31 carrying the roller 16 by means of a pin 35 passing through these branches. The roller 16 comprises two sets of discs 36, each set having several adjacent discs of different diameter, decreasing from the center to the extremity of the roller. The outline of the roller is an are having a radius corresponding to that of the pipe 17. The edges of these discs are provided with zig-zag ribs.

The six arms 15 are displaced by an angle of 30 relative to the six arms 21, although they have been represented as being in the same plane in FIG. 1, in order to simplify the drawing. Sockets 9 and 10 carrying arms 15 and 21 are placed adjacent to one another on the central shaft 1 and they can only turn together on the shaft, as

they are connected to one another by means of bolts 11 which are alternately disposed on both sockets. The two sockets 9 and 10 cannot separate because they are held together by the two nuts screwed on the threaded ends of the shaft 1. v

In order to regulate the pressure of the rollers 16 and 22 against the inner surface of the pipe 17, a device is provided for simultaneously setting both parts of the centering device. For this purpose hexagonal plates 24, 23 engage the sockets 9 and 10, respectively, which plates are connected together by means of three rods 25 which in order to receive the screw 26 which fixes it to the plate 24.

Three screws 27 pass through the backing plate 23 and engage the threaded holes in the collar 18. When these screws are tightened, the plate 23 and the plate 24 approach the joint members 19 and 14 of the arms 21 and 15, for the purpose of straightening out the arms 21 and 15 and to increase the pressure of the rollers 22 and 16 against the inner surface of the pipe 17. The pressure is reduced by releasing the screw 27. The sides of the hexagonal plates 23 and 24 are bevelled in order to provide a good supporting surface for the knuckles 13 and 19.

The propulsion devices 3 and are identical except for one detail. Only the forward propulsion device 3 is described. The propulsion device 3 comprises a socket 37 in engagement with the shaft 1 and secured thereto against rotation by means of a key 4. The socket of the rearward device 5 is retained in the same manner by a key 6 disposed at an angle of 30 relative to the key 4.

The socket 37 is connected with a support plate 38, which may be of circular shape, extending perpendicular to the axis of the socket and provided, at its front end, with twelve reinforcing radial ribs 39. A calotte or cap 40 is welded to the sleeve and to the edge of the plate 38, with the ribs 39 resting against the internal surface of the cap. Thus there are twelve radial compartments each provided with a water inlet 43 in the plate 38 and an outlet 41 on the cap 40. In each of the outlet holes a nozzle 42 is threadedly received which injects the water toward the inner surface of the pipe 17. The rearward propulsion device 5 is not provided with nozzles. Against the rear face of the plate 38 six flexible elements 56 are fixed with their narrow end, which are constructed in the following manner. Between three leather discs 48 in the form of a sector of a circle and having a width of substantially 60, are intercalated two thin stiffening plates 49 and 49a of steel or the like. Over this set of plates and discs piled up together is attached a load plate 50 of trapezoidal shape. This heavy plate is secured by means of several bolts 51 and 52 having their round flat heads on the side of the leather and steel plates and the threaded ends on the side of the load plate 50. Tightening of the bolts draws the bolt heads into the leather discs.

Both the stiffening plates 49 and 4911 are shorter than the leather discs; the length of plate 49 is almost twothirds of the circular leather sectors while the length of the plate 49a is nearly six-tenths of the sector 48. As for this difference in length, the bolts 51 of the exterior row pass through the three leather discs and the two steel plates, while the bolts 52 of the inner row pass only through the leather discs and the larger steel plate 49. Disc 49a is intentionally shorter to avoid a breaking of the leather disc adjacent to the load plate 50. In each circular sector the center portion is cut and is fixed between a ring 45 coaxial with the socket 37 and the plate 38. For this purpose the plate has six threaded bolts 44 alternating with six pins 47 to which the sectors or sections 56 and the rings 45 are secured. Each bolt receives a tightening nut 46 which enters a corresponding aperture of the ring 45 leaving a certain amount of play. The pins 47 enter with slight friction into corresponding holes of the ring 45 in order to make the ring stable relative to the plate 38, which is an essential condition so that the sector or section 56 will be firmly supported.

The disc 48 could be made of synthetic material, such as nylon, possibly reinforced with steel wires to increase the flexibility. The sectors 56 when mounted on the plate 38 present edges defining a circumference of a diameter slightly larger than that of pipe 17. Consequently, when the propulsion unit is introduced in the pipe, all the sectors are rearwardly inclined. The space 4 53 left between the adjacent sectors 56 is slightly V- shaped.

Both the propulsion devices 3 and 5 are angularly displaced relative to one another and axially immovable with respect to each other. The sockets 9 and 10 carrying the centering arms 15 .and 21 are, in turn, mounted rotatably on shaft 1. To facilitate the rotation, lubricant is introduced between sockets 9 and 10 and shaft 1 by means of a grease-cup threadedly mounted in the holes 36a provided in the sockets 9 and 10 and in a sleeve of a tie-beam 36 placed between socket 10 and the socket of rearward propulsion device 5.

It should be noted that the sectors 56 of the forward propulsion device are more flexible than the sectors of the rearward propulsion device. To obtain this result the leather discs 48 of the forward device 3 may be thinner or of more flexible material, or the plates 49, 49a may be of different material than those of the rearward device 5.

The operation of a pipe descaling apparatus provided with the propulsion unit described is as follows. It is not-ed that this apparatus comprises tools placed ahead of the propulsion unit adapted to smash the incrustations and remove them from the inner surface of the pipe, and to the rear of the propulsion unit tools are provided to crush the remaining soft incrustrations and squash them against the surface in order to complete the removing work performed by the forward tools.

It is known that if a valve for regulating the discharging of water from a pipe is shut and opened, certain disturbances are caused which are of a certain duration and of a certain force, depending on the operating speed. These turbulent conditions are created by the momentum of moving water according to the law of energy conservation, and manifest themselves as a variation of the flow and of the speed of water delivery and variation of the pressure, creating the well-known phenomenon of water-hammer. These effects manifest themselves also on the element which provoked the change in flow. These effects are utilized by the propulsion unit in accordance with the invention described. As the apparatus is introduced into the pipe to be cleaned, the water is made to flow into the pipe up-stream of the apparatus and initially the apparatus is pushed with a force of compression of almost five atm. in the case of a pipe having a diameter of 600 mm. The water flows in the pipe and partly passes beyond the apparatus as it finds a path through the V slits existing between the flexible sectors 56 of both propulsion devices 3 and 5 as well as through the holes 43 and nozzle 42, but in reduced quantity. The water exerts a pushing force on the whole propulsion unit and as sectors 56 are movable, it pushes those of the rearward propulsion device, which are suddenly stopped when they engage the plate 38 which carries them. These sectors, which are weighted by the plates 50, transfer their kinetic energy to the plate. At the same moment these sectors are stopped by the plate, the column of water in the back of them is suddenly impeded in its forward flow. This generates a waterhamm-er, the force of which is added to the force already exerted on the rearward propulsion devices. The resultant effect causes the propulsion unit to jump forward. In succession the water column which is in space B between both the propulsion devices, exerts a similar action on the sectors of the forward propulsion device, which remained rearwardly inclined by inertia during the acceleration of the propulsion unit caused by the first waterhammer blow. A second water-hammer blow is then exerted on the propulsion unit as the sectors of device 3 contact their plate. Meanwhile the rear water column -has maintained its force on the rearward device 5. This results in a new forward jump of the propulsion unit and the inertia causes the sectors of the rearward device to be held back. These sectors thereupon contact their plate again due to the effect of water pressure, generating another water-hammer blow which drives the propulsion unit another jump forward. This action is repeated alternately on the forward propulsion device and on the rearward propulsion device. The speed of an apparatus having a propulsion unit such as described can reach 1 meter/second, with an average frequence of 6 to 10 blows per second. During the operation, water pressures are distributed as follows: 0.5 atm. up-stream to the rear device (instead of 5 atm. initially); in space B the pressure is 0.15 to 0.25 atm. It is to be understood that this is in the case of a 600 mm. diameter pipe.

Having now describedmy invention with reference to the embodiment illustrated in the drawings, I do not wish to be limited thereto, but what I desire to protect by Letters Patent of the United States is set forth in the appended claims.

I claim:

1. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, 21 set of flexible sections secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, and a load plate mounted on each said flexible section, said flexible sections extending radially outwardly of said support plate and beyond said load plate and defining a periphery for engaging the inner surface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows effective on said support plate.

2. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, a set of flexible sections secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, and a load plate mounted on each said flexible section, said flexible sections extending radially outwardly of said support plate and beyond said load plate and defining a periphery for engaging the inner surface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to Water pressure against said sections and their support plate to generate water hammer blows effective on said support plate, said sets of flexible sections comprising sectors of relatively soft material and resilient metal plates disposed intermediate said sectors and said periphery defined by said sections being the arc of a circle of greater diameter than the conduit in which it is employed.

3. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, 21 set of flexible sections secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, and a load plate mounted on each said flexible section, said flexible sections extending radially outwardly of said support plate and beyond said load plate and defining a periphery for engaging the inner vsurface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows effective on said support plates, said sets of flexible sections comprising sectors of relatively soft material and resilient metal plates disposed intermediate said sectors, said periphery defined by said sections being the arc of a circle of greater diameter than the conduit in which it is employed, and said metal plates being of shorter length than said sectors.

4. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, a set of flexible sections secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, .and a load plate mounted on each said flexible section, said flexible sections extending radially outwardly of said support plate and beyond said load plate and defining a periphery for engaging the inner surface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows effective on said support plate, said support plates presenting radially disposed ribs on the side opposite the side on which said sections are mounted, each said plate being secured to a sleeve mounted on said shaft, a cap being mounted with its center portion on said sleeve and having its border extending around said plate and forming with said ribs compartments, and each said compartment having a water inlet defined in the support plate and a water outlet defined in said cap.

5. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends 4 and centering means extending between said devices,

each said propulsion device including a support plate concentric with and mounted on said shaft, a set of flexible sections secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, and a load plate mounted on each said flexible section, said flexible sections extending radially outwardly of said support plate and beyond said load plate and defining a periphery for en gaging the inner surface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows effective on said support plate, said centering device comprising a pair of collars mounted on sockets rotatably supported on said shaft and each supporting a radially extending plate, a plurality of flexible arms being hingedly mounted in inclined position on each said collar, each said arm supporting a roller adapted to engage the inner surface of a conduit, said plates on said socket being connected with one another and movable against said arms to regulate the pressure of said rollers against the conduit.

6. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, a set of flexible section secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, and a load plate mounted on each said flexible section, said flexible section extending radially outwardly of said support plate and beyond said load plate and defining a periphery for engaging the inner surface'of a conduit being cleaned,

said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows effective on said support plate, said centering device comprising a pair of collars mounted on sockets rotatably supported on said shaft and each supporting a radially extending plate, a plurality of flexible arms being hingedly mounted in inclined position on each said collar, each said arm supporting a roller adapted to engage the inner surface of a conduit, said plates on said sockets being connected with one another and movable against said arms to regulate the pressure of said rollers against the conduit, the means connecting said plates on said sockets including a plurality of tubes extending parallel to each other and to said shaft and through one said collars, said one collar having a plurality of threaded apertures and said plates on said socket adjacent said one collar having apertures for screws extending therethrough and into said threaded apertures.

7. A propulsion vunit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, a set of flexible sections secured to said plate in spaced relationship with each other defining a disk shaped device with gaps between adjacent sections, and'a load plate mounted on each said flexible section, said flexible sections, extending radially outwardly of said support plate and beyond said load plate end defining a periphery for engaging the inner surface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows, effective on said support plates, said sets of flexible means comprising sectors of relatively soft material and resilient metal plates disposed intermediate said sectors, said periphery defined by said sections being the arc of a circle of greater diameter than the conduit in which it is employed, threaded bolts extending from said support plate and said flexible sections being secured to said support late at their lower ends by means of said bolts, and a ring being mounted over said lower ends on the side opposite said support plate.

8. A propulsion unit for apparatus for descaling conduits such as pipes, sewers and the like comprising, in combination, a pair of propulsion devices, a center shaft supporting one said propulsion device at each of its ends and centering means extending between said devices, each said propulsion device including a support plate concentric with and mounted on said shaft, a set of flexible sections secured to said plate in spaced relation-' ship with each other defining a disk shaped device with gaps between adjacent sections, and a load plate mounted on each said flexible section, said flexible sections extending radially outwardly of said support plate and beyond said load plate and defining a periphery for engaging the inner surface of a conduit being cleaned, said sections and load plates of said propulsion devices being movable alternately in response to water pressure against said sections and their support plate to generate water hammer blows effective on said support plate, said centering device comprising a pair of collars mounted on sockets rotatably supported on said shaft and each supporting a radially extending plate, a plurality of flexible arms being hingedly mounted in inclined position on each said collar, each said arm supporting a roller adapted to engage the inner surface of a conduit, said plates on said sockets being connected with one another and movable against said arms to regulate the pressure of said rollers against the conduit, said flexible arms on one said collar being angularly displaced with respect to the arms on the other said collar by an angle corresponding to one-half the angular width of one said flexible sections.

References Cited by the Examiner UNITED STATES PATENTS 1,593,072 7/1926 Haydock et a1. l5104.06 2,972,156 2/1961 Ver Nooy 15104.06 3,130,431 4/1964 Reinhart l5l04.06

CHARLES A. WILLMUTH, Primary Examiner.

EDWARD L. ROBERTS, Examiner. 

1. A PROPULSION UNIT FOR APPARATUS FOR DESCALING CONDUITS SUCH AS PIPES, SEWERS AND THE LIKE COMPRISING, IN COMBINATION, A PAIR OF PROPULSION DEVICES, A CENTER SHAFTS SUPPORTING ONE SAID PROPULSION DEVICE AT EACH OF ITS ENDS AND CENTERING MEANS EXTENDING BETWEEN SAID DEVICES, EACH SAID PROPULSION DEVICE INCLUDING A SUPPORT PLATE CONCENTRIC WITH AND MOUNTED ON SAID SHAFT, A SET OF FLEXIBLE SECTIONS SECURED TO SAID PLATE IN SPACED RELATIONSHIP WITH EACH OTHER DEFINING A DISK SHAPED DEVICE WITH GAPS BETWEEN ADJACENT SECTIONS, AND A LOAD PLATE MOUNTED ON EACH SAID 